2.14. System of ignition

The system of ignition of petrol engines provides ignition of air-fuel mix by means of the spark created by the ignition coil. In the ignition coil current of low voltage (12B) will be transformed to a high-tension current (25000–30000 V).

VW T4 engines are equipped with completely electronic systems of ignition and injection of fuel. In this section the description system of ignition. Arrangements of components see on rice. System of ignition and injection of Digifant.

The electronic system of ignition is reliable, works practically without wear and within service of adjustment and repair does not demand.

The system of ignition consists from:

 – spark plugs;
 – transformer of high voltage (coil of ignition, device of switching off, final step);
 – the ignition distributor with Hall's sensor;
 – Digifant injection devices.

Systems of ignition and injection have the general electronic control unit which has memory for record of malfunctions. If during the movement in an electronic part of the engine malfunctions appear, then they register and kept in memory.

Before repair of system of ignition it is necessary to interview memory of the monitor in the beginning. Memory is interviewed by the reading-out VW1551 device via black and white diagnostic plugs of a box of safety locks. The reading-out device, as a rule, is inaccessible to the fan and therefore it is recommended to make interpretation of malfunctions at car repair shop.


During the works in electronic system of ignition it is necessary to observe special safety measures (see subsection 2.14.2).